Carburetor throttle control



Dec. 3,1946.

Filed April 5, 1943 e7 @P. 1 INVENTOR L9 ,6 5 20 J.-FRANK WEAKLE F G. 3. M 4

ATTORNEY which y'atented 3w. 3, i

CARBURETOR THROTTLE CONTROL John Frank Weakley, St. Louis, Mo., minor to Carter Carburetor Corporation, St. Louis, him, a corporation of Delaware Application April 5, 1943, Serial 'No. 481,846

7 Claims.- (01. 137-139) l This invention. relates to valve controlling means for internal combustion engines and more particularly to means for controlling the throttle valve thereof. 4

In the usual form of carburetor for internal combustion engines there is provided a butterfly type throttle valve having readily accessible means for adjusting the maximum closed position to which the valve can be moved by the throttle return spring for normal idling. Ordinarily, the idling adjustment is effected by means of a screw, carried by thethrottle arm, which engages a fixed abutment on the carburetor body to limit the throttle closing movement. However, if the idle adjusting screw should be withdrawn too far, the powerful throttle return spring may wedge the throttle plate within the carburetor barrel resulting in sticking of the valve and damage to the valve plate and-barrel. This possibility is of particular importance where the throttle is slot 22. .T'hese parts comprise substantially a the carburetor barrel.

by means of a screw IS. The spring strip is secured at its other end to a coiled spring I] which is partially threaded on theextremityof an adjusting screw l8 pivoted at IS. The cam lever,- and spring are enclosed within a governor housing mounted on the side of the carburetor barrel.

Screw It extends into an extension 2| of the housing where it is provided with an adjusting known governor in which spring l1 constantly tends to open the. unbalanced throttle plate 8 against the force of air now downwardly through A projection on cam lever I4 is adapted to engage a stop 26, secured to the inner wall of.

, housing l9 by an eccentric screw 21, just as the throttle plate reaches its .fully closed position.

The setting of this eccentric is permanently effected in the factory as'a part of the assemblyof the governor type'in which the governor spring. 1

' by preventing wedging of the throttle valve plate and, additionally, providing means for positively opening the valve in case of non-functioning of said first means or the governor spring.

This object and' other more detailed objects hereafter appearing are attained by-the device illustrated in the accompanying drawing in Fig.1 is a side view of part of a carburetor embodying the invention, portions being sectioned for clearer illustration.

Fig. 2 is a partial 'side view and section taken substantially on the corresponding section line of Fig. 1.

Fig. 3 is a partial side view and section taken on the line 3-3 of. Fig. 1 and Fig. 4 is an elevation showimg the throttle opings l0 and H and projecting therebeyond at,

both ends.

On the left hand end of the throttle shaft,

(Figs. 1 and 3)' there is rigidly attached a camlike lever M to which is secured a spring strip I5 ing operation and, in service, it igunacces'sible except upon removal of cover 28. The slot in screw 21 may be closed to further defy tempering. On the. other end of throttle shaft 9 there is provided a lever having opposed'arms 28 and 30,

the former being pinned at 3| to a iink32 c'onnected to piston 33 slidable in dash' pot cylinder 34 which functions to dampen pulsations of the throttle valve. This arm is also provided witha lip 35 for a purpose to be mentioned later.

The above parts are received within-a casing 36 which is formed .as an integral part of the carburetor'barrel. and is provided with a cover plate 31. This cover plate is centrally enlarged at 38 and journals a stub' shaft 39 to the inner end of Control arm 42 is also provided with a thread- 7 ed boss 45 receiving idle adjusting screw 48 disposed to engage an abutment "on cover plate 31. Normally, screw 46 will be adjusted so that the throttle valve'will be held slightly open during normal idling, permitting suflicient air to pass the throttle to form a suitable combustible mixture with the idling fuel emerging from port 8d. Thus; projection Zion cam lever inner will not contact eccentric 26, However, since adjusting screw GB is readily accessible and is frequently adjusted by unskilled persons asv well as mechanics, this screw may be withdrawn when the accelerator pedal is released. Finger ti on the stub shaft normally has no function,

since when return spring 44 is counteracted by depressing of the accelerator pedal, the throttle plate will be moved openward to the extent permitted by the counterforce of the air flow through the carburetor and the positioning of finger ll.

However, in case of failure of spring ll because of sticking of the throttle or for any other reason,

and also should eccentric 21 or finger 28 be excessively worn or damaged, so as not to function properly, finger ll on the throttle control lever will engage lip 35 on arm 20, when the accelerator pedal is fully depressed, to positively p n the throttle a slight amount. while the substantially complete governing-range of the throttle is not afiected. Thus, the carburetor will remain operative to run the engine at a slow speed even though the governor should fail.

- The type of carburetor and governor shown are not essential and, in fact, the emergency-mechanism may be varied as will occur to those skilled in the art; The exclusive use of all such modifi- I g means, structure movable with said throttle, abutment structure adjacent said structure, a

an idle adjusting screw mounted in said structure for adjustably limiting'the closing of said throttle to i position, and an-addltional device cooperab le with said structure to permanently prevent closing of said'throttle far enough to cause wedging and sticking thereof in said conduit.

4.1a combination with an internal combustion engine intake conduit havinga butterfly throttle therein, spring means to open said throttle, more powerful sp m.- means for closing said throttle,

manual means to retract said latter spring means to permit opening of said throttle by said first spring means, arm structure movable with said throttle, an abutment adjacent said structure, an idle adjusting screw carried'by said structure and cooperable with said abutment to ii: the idling position of said throttle, and an additional device cooperable with said arm structure to permanently prevent closing of said throttle far enough 7 I to cause wedging thereof in said conduit.

5. in combination with aninternal combustion engine intake conduit having a throttle therein and main and idling fuel supply systems, means to nearly close said throttle for normal idling, meansto adjust the idling position otsaid throttie, and means to permanently limit closing means.

cations as some wit the scope of the appended said throttle 101? normal idling. and an additional.

- less accessible device to "prevent closing of said valve far enough to cause wedging or sticking thereof in said conduit.

2. In combination with an internal combustion engine intake conduit, a throttle therein, means to yieldingly open said throttle, manual throttle control mechanism including a spring for normeans, a readily accessible adjusting device for limiting the closing of said throttle to a partially open, normal idling position, and an additional" device limiting ,the closing movement of said throttle to prevent wedging and sticking thereo in said conduit.

"mally closing said throttle against said yielding 3. In combination with an internal combustion engine intake conduit, a throttle therein, means to yieldingly open said throttle. manual throttle control mechanism including a spring for normally closing said-throttle against saidyielding s. in combination with an internal combustion engine intake conduit, a flow responsive butterfly throttle therein, yielding means to open said throttle, manual control mechanism including a throttle return spring more powerful than said yielding means, arm structure movable with said throttle, idle adjusting screw carried by said ins screw. v i

Z. In combination with an internal combustion 1' --'t-'- e intake conduit, a butterfly throttle thereinand responsive to pressure in said conduit, a

spring normally tending to open said throttle,

' throttle control mechanism including a part for closing said throttle at the will of the operator, a k

device for adjustably limiting the closing of said throttle to idling position, and a protective device for preventing-closing of said throttle far enough to cause sticking thereof, said controimechanism also including a part constituting a one-way operative connection with said throttle for insuring opening of said throttle in case of non-function- 'ing oi said opening spring of said protectivedemice.

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